kubernetes#60525 introduced
Balanced attached node volumes feature gate to include volume
count for prioritizing nodes. The reason for introducing this
flag was its usefulness in Red Hat OpenShift Online environment
which is not being used any more. So, removing the flag
as it helps in maintainability of the scheduler code base
as mentioned at kubernetes#101489 (comment)
NodeInfo.Allocatable.ScalarResources already knows which resources
are scaler. Also, if the resource name is not present,
it's pointless to compute score for a resources the node can not allocate
since nodeInfo.Allocatable.ScalarResources[resource] is zero for the case.
And both leastRequestedScore and mostRequestedScore returns 0 score
for nodes with zero allocatable resource.
The balancedResourceScorer deals only with CPU and memory which
are not scalable resources.
